Admixing apparatus



ADMIXING APPARATUS Filed Aug. 17, 1964 CONTROL.

CONTROL CONTROL CONTROL VALVES g VALVES 23 VA LVE8 4 United States Patent T 12 Claims. (01. 222-s7 This invention relates to devices for mixing liquids and the like.

This invention relates to improvements in devices for the admixing of a liquid additive to a main medium which is flowing under pressure and comes from an admixing container disposed in a subsidiary pipe leading to a venturi insert in a main pipe and branched off from the main pipe before the insert, wherein, after the displacement of the admixing medium out of the admixing container, due to the using-up of the supply, a shut-off valve is actuated in the subsidiary pipe.v

Further, the present invention relates to improvements in devices of the aforesaid type in which two admixing containers are connected parallel to each other in the subsidiary pipe and the shut-off valves associated with them are designed as alternatingly influencing changeover valves and in which, if the supply in one of the admixing containers is about to be exhausted, the other container is connected to the venturi insert, so that the empty container can be replenished.

A device provided according to the present invention is such that it requires no supervision due to an arrangement whereby replenishment is automatically effected in accordance with change-over from one admixing container to the other. The device of the present invention is characterised in that each of the compartments of the two admixing containers containing the medium to be admixed is connected to a replenishing container via a pipe in which there is disposed a valve (replenishment valve) controllable in such manner that it is closed in the admixing position in which the admixing container associated with it is connected via the opened, associated shutoff valve to the venturi insert. According to a preferred embodiment, the replenishing valves are non-return valves.

This arrangement has, inter alia, the advantage that a larger but simply-designed storage container can be used together with small admixing containers.

Further features of the invention and further advantages thereof will be disclosed in the following detailed description, reference being made to the drawing, wherein the sole figure shows, in diagrammatic form, one of the possible embodiments of the invention.

In the drawing, the main medium flows through a main pipe 1 and may, for example, be extinguishing water in a fire extinguisher or a fire extinguishing plant which is to have a foaming agent mixed with it as an admixing agent, the water flowing through a venturi insert 2 in the main pipe.

Before the venturi insert, as seen in the direction of flow, there branches off from the main pipe 1 a subsidiary pipe 3 which divides up at 18 in order to be. connected to the two admixing containers 5a and 5b.

Between the containers 5a and 5b and the pipe branch 18, there is in each case an electrically reversible threeway valve 4a and 4b. The branches 19m and 19b of the subsidiary pipe open out into the admixing containers each of which is subdivided by a diaphragm 6a or 6b into a chamber 16a or 16b for the admixing medium and a water chamber 15a or 15b for the main medium, said branches opening into the main medium chambers in each case.

Connected to each of the admixing medium chambers 3,224,637 Patented Dec. 21, 1965 is a pipe 8a or 8b these being both inlet and also outlet pipes. It is not necessary to provide a separate filling inlet. The pipes 8a and 8b are divided up at 20a or 20b into the pipes 21a and 22a or 21b and 22b. The pipes 21 lead, via valves 9a which are locked relatively to each other, i.e. which alternatingly open and close, into the common pipe 10 which opens into the venturi insert 2. The pipes 22 lead, via valves 23a and 23b into a common pipe 24 which obtains the admixing medium .from a high-level container 25 and feeds it to the chambers 16 via the pipes 22 and 8. The valves 23 may be so locked relatively to each other that one closes when the other opens, and vice versa. It will suflice also to provide simple nonreturn valves which allow the passage of the admixing medium out of the container 25 only in the direction of the chamber 16.

Each of the four chambers 15 and 16 has also a manually actuated venting valve 26a and 27a or 26b and 27b leading to the exterior.

As a third pipe, there is connected to each of the two three-way valves 4a and 4b a pipe 28a and 28b, operating as a discharge pipe. These pipes 28a and 28b open out into a discharge arrangement 29, which is a vessel open at the top and having an overflow 30.

Each admixing medium chamber has a sensing means 12a or 12b which supplies a signal when the resilient diaphragm 6 of the chamber concerned has been deformed to such an extent that it contacts the sensing means. This occurs when the diaphragm subjected to the pressure of the main medium in the chamber 15 has to a considerable extent displaced the admixing medium out of the chamber 16 and has thereby sufficiently diminished the size of the chamber 16.

The control of the valves 9 and 4 and where appropriate also 23 influenced by the sensing means 12 may be electrical, hydraulic, pneumatic or even mixed control arrangements. In general, the electrical control method is preferred. It will, however, be unnecessary to give a more detailed description of this control arrangement, since a person skilled in the art will experience no difliculty therewith.

To indicate how the apparatus works, it will next be assumed that the admixing medium has just been displaced out of the chamber 16a such as is effected when the pressure liquid in the pipe 1 presses, via the pipe 3 and the valve 4a through the branch 18 and pipe 19a into the chamber 15a. The non-return valve 23a prevents return flow to the container 25. Thus, the admixture medium flows via the pipe 8a and the branch 20a through the valve 9a which is now open in the pipe 21a and from there through the pipe 10 into the venturi insert 2. The path to branch 20b is blocked by the valve 9b which is at this time closed.

At the same time, the valve 4b is so disposed that it opens a path from the chamber 15b to the discharge pipe 28b, but blocks the path between the branch 18 and pipe 28b. Thus, the container 5b is separated from the pressure pipe 3 by the valve 4b and by the valve 9b from the admixing container 5a. Furthermore, the free discharge passage has been opened in the chamber 15b, so that the admixing medium from the high-level container 25 flows via the pipe 24 and the non-return valve 23b, which is now open, into the chamber 16b and, by the means of the diaphragm 6b, expels the water which is now no longer subjected to pressure out of the chamber 15b to the discharge arrangement 28b, 29.

When the sensing means 12a responds, because the diaphragm 6a presses against it, it switches over the valves 4a, 4b and 9a for example electrically by means of a relay, or in some other known manner. The valves 9a and 9b can of course also be combined to form a switch over valve for example in the form of a three-way valve. Due to this switch-over, the elements of the arrangement designated by the index a exchange their function with those having the index b. The admixing medium is then expelled from the chamber 16b into the pipe 10, whereas further admixing medium flows from the container 25 into the chamber 16a and is there stored until the next change-over takes place. The pressure water from the pipe 3 flows into the chamber 151;, whereas the pressureless water from the chamber 15a flows via the valve 4a into the discharge arrangement 29.

The manually actuated venting valves 26 and 27 permit initiating the operations.

It is not entirely necessary that the valves 9a and 9b should be electrically controlled. If they are designed as non-return valves having a corresponding through-flow direction, it will sufiice simply to reverse the valves 4a and 4b.

By means of the design of the discharge arrangement discussed here, any possibility is prevented of air being drawn into a chamber 15 after the emptying of the said chamber and via the associated pipes 28 and 19, so that adequate pressure can no longer build up therein and the admixing medium flows out of the admixing medium chamber of the other container, via the corresponding non-return valve 9, into the admixing pipe 10.

I claim:

1. Apparatus for admixing a liquid additive to a principal liquid, said apparatus comprising a pipe for conveying said principal liquid under pressure, a source of said additive, first and second containers adapted to receive additive from said source, valve means for selectively and alternately coupling said containers to said pipe and to said source, pressure responsive means operatively coupled to said containers and to said pipe to respond to the pressure of the principal liquid in the pipe to urge additive from the containers via said valve means into said pipe, and sensing means to sense the exhausting of additive from said containers and to control said valve means so that one container is being filled from said source while additive is dispensed by the other container into said pipe.

2. Apparatus as claimed in claim 1, comprising venting means on the containers to enable filling the same with said additive.

3. Apparatus as claimed in claim 1, wherein the pressure responsive means includes a diaphragm on each container dividing the latter into compartments into one of which flows said principal medium, said apparatus further comprising control means to discharge the principal medium from the compartment containing the same as the corresponding compartment is being filled withadditive.

4. Apparatus as claimed in claim 2 wherein said sensing means includes means to sense displacement of said diaphragms.

5. Apparatus as claimed in claim 4, wherein said valve means includes a first pair of valves coupling said source to respective of said containers.

6. Apparatus as claimed in claim 5, wherein said valve means includes a second pair of valve alternately connecting the containers to the pipe for alternative discharge of additive into the latter.

7. Apparatus as claimed in claim 6, wherein said pressure responsive means further comprises a subsidiary pipe connected to the first said pipe and including two branches, said control means connecting said branches to respective compartments in said containers and selectively coupling the latter said compartments to discharge and to said branches.

8. Apparatus as claimed in claim 7, wherein the control means are three-way valves.

9. Apparatus as claimed in claim 18, wherein the first pair of valves are one-way valves.

10. Apparatus as claimed in claim 8, wherein the second pair of valves are one-way valves.

11. Apparatus: as claimed in claim 8, wherein the first pair of valves are interchangably opened and closed.

12. Apparatus as claimed in claim 8, wherein the second pair of valves are interchangeably opened and closed.

References Cited by the Examiner UNITED STATES PATENTS 1,875,023 8/1932 Krueger -e 222386.5 X 2,819,679 1/1958 Wilson 222386.5 X 3,166,096 1/1964 Lang 222386.5 X

LOUIS J. DEMBO, Primary Examiner.

HADD S. LANE, Examiner. 

1. APPARATUS FOR ADMIXING A LIQUID ADDITIVE TO A PRINCIPAL LIQUID, SAID APPARATUS COMPRISING A PIPE FOR CONVEYING SAID PRINCIPAL LIQUID UNDER PRESSURE, A SOURCE OF SAID ADDITIVE, FIRST AND SECOND CONTAINERS ADAPTED TO RECEIVE ADDITIVE FROM SAID SOURCE, VALVE MEANS FOR SELECTIVELY AND ALTERNATELY COUPLING SAID CONTAINERS TO PIPE AND TO SAID SOURCE, PRESSURE RESPONSIVE MEANS OPERATIVELY COUPLED TO SAID CONTAINERS AND TO SAID PIPE TO RESPOND TO THE PRESSURE OF THE PRINCIPAL LIQUID IN THE PIPE TO URGE ADDITIVE FROM THE CONTAINERS VIA SAID VALVE MEANS INTO SAID PIPE, AND SENSING MEANS TO SENSE THE EXHAUSTING OF ADDITIVE FROM SAID CONTAINERS AND TO CONTROL SAID VALVE MEANS SO THAT ONE CONTAINER IS BEING FILLED FROM SAID SOURCE WHILE ADDITIVE IS DISPENSED BY THE OTHER CONTAINER INTO SAID PIPE. 